EurekAlert July 13, 2020 To realize the full potential of nanoelectronic devices based on 2D materials they have to be placed on the appropriate substrate, and an insulator layer is also needed on top of it, an insulator that is extremely thin and of extremely good quality. An international team of researchers (Austria, Russia, China, USA – UT Austin, Germany, Italy) has achieved excellent results with special crystals containing fluorine atoms. A transistor prototype with a calcium fluoride insulator has provided convincing data, and other materials are still being analysed. The new electrically conductive 2D materials can be combined with […]
Tag Archives: Advanced materials
New organic material unlocks faster and more flexible electronic devices
Science Daily July 15, 2020 Long-range and fast transport of coherent excitons is important for the development of high-speed excitonic circuits and quantum computing applications. By precisely stacking carbon and hydrogen molecules one over the other researchers in Australia have designed an organic semiconductor. The material is just one carbon atom thick which gives it the flexibility to be bent into any shape. The material is biodegradable or easily recyclable, thus avoiding the tonnes of e-waste generated by current generation electronic devices…read more. Open Access TECHNICAL ARTICLE
Underused part of the electromagnetic spectrum gets optics boost from metamaterial
Phys.org July 14, 2020 Terahertz radiation potentially has applications in next-generation wireless communications (6G/7G), security systems, biomedicine, etc. because of the lack of appropriate materials and sophisticated optical components for flexible control of terahertz waves. Researchers in Japan have engineered a 2.28-µm ultra-thin terahertz metasurface collimator with a high directivity of 4.6 times consisting of 339 pairs of meta-atoms compared with a single terahertz continuous-wave source. The metasurface exhibits an extremely high refractive index of 15.0 and a low reflectance of 15.5% at 3.0 THz. It should facilitate ground-breaking applications such as arbitrary phase converters, solid immersion lenses, and cloaking…read more. […]
Harvesting hydrogen from nanogardens
Nanowerk July 3, 2020 By manipulating (electro)chemical gradients using a combined hydrothermal and electrodeposition strategy, an international team of researchers (China, the Netherlands) has shown the controlled growth of Co(OH)2 nanostructures, mimicking the process of garden cultivation. The resulting “nano-garden” can selectively contain different patterns, all of which can be fully phosphidated into CoP without losing the structural integrity. Under pH-universal conditions, the CoP “soil + flower-with-stem” structure shows a much more “effective” surface area for gas-evolving reactions with lower activation and concentration overpotentials. This provides superior bifunctional catalytic activity for both reactions, outperforming noble metal counterparts…read more. Open Access […]
New biomaterial could shield against harmful radiation
Phys.org July 8, 2020 Melanins are a family of heterogeneous biopolymers found ubiquitously across plant, animal, bacterial, and fungal kingdoms where they act variously as pigments and as radiation protection agents. An international team of researchers (USA – Northwestern, UC San Diego, University of Akron, Belgium) synthesized ” selenomelanin” enriching melanin with selenium instead of sulfur to provide better protection against X-rays as selenium is an essential micronutrient that plays an important role in cancer prevention. Results demonstrated that selenomelanin offers superior protection from radiation, it is easy to synthesize. Selenomelanin can be biosynthesized, with appropriate nutrients can produce selenomelanin […]
New quantum materials with unique properties
Nanowerk June 23, 2020 Researchers in Germany are working on a German Research Foundation funded project that focuses on novel physical phenomena of solids resulting from a particularly strong coupling between a material’s elastic properties and its electronic quantum phases. Based on the findings obtained, the researchers expect to produce new quantum materials with extraordinary properties and open the application potential resulting from interactions between mechanical and electronic properties…read more.
A new platform to stretch 2D materials
Nanowerk June 17, 2020 As the electronic and optical properties of 2D materials can be controlled by mechanical deformations of their crystal structure, strain engineering can be used to modify their electronic properties. Researchers in Spain have developed thermal strain actuators on top of polypropylene substrates to control the biaxial strain in atomically thin MoS2 layers. The actuators can reach a maximum biaxial strain of 0.64 % and reliably modulated at frequencies up to 8 Hz. The strain levels can be varied all the way from 0% to 0.6% with a negligible spatial drift. They demonstrated the operation of the […]
Metasurface opens world of polarization
Science Daily June 3, 2020 To achieve broad polarization manipulation, multiple birefringent materials need to be stacked one top of another making these devices bulky and inefficient. Researchers at Harvard University used topological optimization to design birefringent materials. They started with the functionality of the metasurface and allowed the algorithm to explore the huge parameter space to develop a pattern that can best deliver that function. The resulting metasurface was composed of nested half circles. The odd shapes have opened a whole new world of birefringence. They can achieve broad polarization manipulations; polarization can be tuned by changing the angle […]
Three research groups, two kinds of electronic properties, one material
Science Daily June 10, 2020 An international team of researchers (Israel, Germany) has shown that Bi2TeI (bismuth, tellurium and iodine ) is a dual topological insulator. It exhibits band inversions at two-time reversal symmetry points of the bulk band, which classify it as a weak topological insulator with metallic states on its ‘side’ surfaces. The mirror symmetry of the crystal structure concurrently classifies it as a topological crystalline insulator. They show the existence of both two-dimensional Dirac surface states, which are susceptible to mirror symmetry breaking, and one-dimensional channels that reside along the step edges. Their mutual coexistence on the […]
Ultra-thin camera lenses of the future could see the light of day
Nanowerk June 11, 2020 The fabrication of state-of-the-art metasurfaces typically involves several expensive, time-consuming, and potentially hazardous processing steps. Researchers in Sweden have developed a method to construct phase-gradient metasurfaces from an exposed standard electron beam resist. They demonstrated the advantages of the method by constructing high-performance flat optics for the entire visible wavelength range. The method dramatically cuts the required processing time, cost, and reduces safety hazards. The method could be a step towards large-scale production of metasurfaces…read more. Open Access TECHNICAL ARTICLE